Rich Fennessy, who most recently was CEO of einstruction Corp., a global tech firm based in Scottsdale, and before that, Insight Enterprises, a Fortune 500 tech company, will take the helm of FishNet Security Inc. replacing retiring CEO Gary Fish.

That's because now, Fish has smaller fish to fry: After building Overland Park, Kan.-based FishNet Security into a $700 million company with more than 700 employees, he wants to focus more of his energy on two earlier-stage tech companies he started.

Fish founded FishNet Security 17 years ago at age 26. Now 44, he will be succeeded by Fennessy. Fish, however, will remain active with FishNet as its chairman and adviser on special projects, including mergers, acquisitions and business development.

One reason Fennessy was selected to succeed him as CEO, Fish said, was Fennessy’s experience leading a public tech company. From 2004 to 2009, Fennessy was CEO of Insight Enterprises, a Fortune 500 tech company with 5,500 employees in 22 countries. His public company experience also includes 17 years with IBM, where he helped build ibm.com into a $12 billion worldwide Web and telephony business.

Fennessy, who lives in Phoenix, will rent an apartment in the Kansas City area and travel back and forth between here and Arizona for the time being, Fish said.

“Then we’ll assess whether we feel he needs to move here permanently,” Fish said. “But FishNet’s always going to be a Kansas City company. Our facilities on the Sprint campus are just phenomenal, and we’re up to 100,000 square feet out there. So we’ve got a big stake in Kansas City.”

FishNet Security, already the largest information security provider in North America, is expected to eclipse $1 billion in revenue within three years. Fish said, “and going public could be a really good outcome.”

But his lack of public-company CEO experience did not factor into his decision to step down from a day-to-day leadership role, Fish said.

Rather, the serial entrepreneur said he wants to focus on building DomoTek, a home automation firm he founded in 2009, and FireMon, which he has grown into a 100-employee company since launching it in 2005.

“It’s appealing to me to now go work full time, as much as ‘full time’ means to me, in that software space,” Fish said in an interview. “And FireMon has an excellent management team. One of my fortés is building good management teams. I always joke that I build good management teams so I don’t have to work as hard.”

With a competent team in place at FishNet, the founder said he began considering handing over that company’s reins after it was acquired in November 2012 by Bahrain-based private equity firm Investcorp SA. Fish sold his majority stake in 2008 to Chicago-based Lake Capital Management LLC. Investcorp bought Lake Capital’s stock and more of Fish’s with a goal of expanding FishNet’s international reach.

“At that time,” Fish recalled, “I told them, ‘Look guys, I don’t know for sure when, but when the time’s right, I’m going to retire.' I decided in February that probably by the end of this year, I’d be ready to retire. So we started a CEO search about eight months ago.”

Fish said the grind of running a later-stage company no longer appealed to him.

“I have self-admitted ADD,” he said. “It’s not diagnosed, but I get bored easily, and that’s part of being an entrepreneur. I like the whole startup and growth phases, where the decisions you make are very visible and you can see the reaction more in real-time.

As an investor and adviser, Fish also is helping local tech startups Front Flip and Data Locker Inc. grow.

Fish’s entrepreneurial career began in 1996, after he earned a degree in electronics technology from DeVry University and worked three jobs, including two years as the “IT guy” for JE Dunn Construction.

He launched FishNet Security as an information technology, not information security, firm.

“But early on, I realized there could potentially be issues with security and the Internet,” said Fish, who decided in 2000 that FishNet would focus 100 percent on cyber security. “It was a fantastic bet. Who could have known back then that it would be the issue it is today?”

Colleagues thought he was crazy for giving up business such as building and hosting websites and creating networks for clients, Fish added.

But he ended up in a sweet spot, where a stroke of good fortune helped him establish an early lead in the booming niche.

At a trade show, Fish explained, he encountered a representative of CheckPoint Software Technologies, which produced the first commercially available firewall. Noticing the rep was having trouble setting up a demo model, Fish offered his assistance and fixed it. That prompted an invitation for FishNet to sell CheckPoint products, which this year will account for about $80 million of the company’s revenue.

Other growth drivers for FishNet have been the five acquisitions Fish has negotiated since 2006. The most recent was announced this month, after FishNet acquired TorreyPoint, a Sunnyvale, Calif., firm that provides strategic network engineering solutions to 400 customers.

Each of the acquisition targets added some capabilities that FishNet didn’t have, Fish said, but the deals were largely geographic plays, intended to extend the company’s national reach.

“When I started FishNet, I used to joke: ‘I don’t want to own the whole U.S. I just want to own the Midwest,’” Fish said. “But I quickly figured out that I needed to own the whole U.S.”

Thus, Fish began approaching other tech entrepreneur-started companies that had reached “an inflection point where they either had to invest to keep growing or sell.”

“Almost all were getting close to $40 million in revenue,” Fish said. “But their expenses were getting a lot bigger; their payrolls were getting a lot bigger. In this space, you either have to go big or stay home. You have to decide to really build something or get swallowed up by the big guys like FishNet.”

In addition to acquisitions, recent strategic developments have included FishNet’s expansion of its managed security services and the opening of its second security operations center in Atlanta. Those offerings provide network and device monitoring and intrusion-response services to large enterprise customers.

Fennessy said he was fortunate to have been chosen to lead the growing company.

“In the technology solutions space, few companies can compare with the depth, breadth and success of FishNet Security,” Fennessy said in a release. “The company is the leading reseller for almost every major security and infrastructure technology vendor, and our more than 300 consultants have proven themselves over and over, having delivered more than 2,000 successful customer engagements in 2013.”

FishNet has 29 offices in the United States and London, but 300 of its 700 employees work in the Kansas City area.